There is a constant need to improve the capacity, efficiency and restriction reduction of air filters used in internal combustion engines in order to enhance efficiency. Radial air filter elements generally comprise an annular filter media which is pleated and has panels which extend axially, so that when the filter is installed in a filter housing for filtering inlet air for internal combustion engines the panels extend vertically and are joined by vertically extending peaks and valleys. With the current arrangement, there is a tendency for particles entrained in the air stream being drawn into the engine to bridge between adjacent the panels and thus cutoff flow of air downstream of the bridge. This reduces the amount of particulate that the filter will hold before being plugged and increases the restriction to air flow since less filter area is exposed to the inlet air stream. Face velocity of the air stream increases which increases impact speed that in turn results in some particles passing completely through the filter media. The increase in restriction due to bridging decreases horsepower and increases fuel consumption. The increased fuel consumption in a vast fleet of cars generates additional air pollution and consumes economical resources which might be otherwise directed.
Reducing restriction is of immediate concern to racing car engines in which immense amounts of air are consumed by an engine over a relatively short period of time. Technology developed for racing car engines is frequently transferable to street vehicles and other machines and therefore has significance far beyond its original use.
In view of these considerations there is a constant need for air filters which have increased capacity and efficiency as well as reduced air flow restriction.